Device and method for minimally invasive tendon sheath release using device with retractable blade and hemi-cannula

ABSTRACT

A device and method for minimally invasive tendon sheath release is presented herein. The device and method enables a surgeon to cut (“open”) a pulley that is obstructing a nodule and keeping a tendon from sliding smoothly. A guide probe of the device is inserted through a small incision and is used to find the edge of the pulley. Once found, the probe is guided to an end of the pulley. Proper placement of the device may be confirmed through the use of ultrasound. After proper position is assured, a hemi-cannula may be moved over the guide probe to isolate the pulley from the surrounding tissue. A retractable cutting shaft is then used to sever the pulley. A dilation device may be inserted prior to the insertion of the spherical tipped guide probe to dilate the area.

CROSS REFERENCE TO RELATED APPLICATION

This application is a divisional of and claims priority to currentlypending U.S. patent application Ser. No. 14/090,683, entitled “Methodfor Minimally Invasive Tendon Sheath Release Using Device withHemi-Cannula”, filed Nov. 26, 2013, which claims priority to U.S. Pat.No. 8,608,765, entitled “Device for Minimally Invasive Tendon SheathRelease”, filed on Oct. 14, 2011, which is a continuation in part andclaims priority to U.S. Pat. No. 8,608,763, entitled “Method forMinimally Invasive Tendon Sheath Release”, filed on Oct. 1, 2010 whichclaims priority to U.S. Provisional Patent Application No. 61/251,957,entitled “Device for Minimally Invasive Tendon Sheath Release,” filed onOct. 15, 2009, the contents of each of which are hereby incorporated byreference.

FIELD OF THE INVENTION

This invention relates to a novel device and method for minimallyinvasive tendon sheath release. More particularly, it relates to adevice and method that allows a surgeon to sever a pulley that isobstructing a nodule without damaging any surrounding tissue.

BACKGROUND OF THE INVENTION

Tendons that move fingers are held in place on bones by a series ofligaments called pulleys (or sheath). These ligaments form an arch on abone surface that creates a fibrous tunnel through which the tendonextends along the extent of the bone. Triggering is usually the resultof a thickening in the tendon that forms a nodule, or knob. The pulleyligament may thicken as well. The constant irritation from the tendonrepeatedly sliding through the pulley causes the tendon to swell in thisarea and create the nodule.

The symptoms of trigger finger include pain and a painful clickingsensation when the finger is bent. Pain usually occurs when the fingeris bent and straightened. Tenderness usually occurs over the area of thenodule. The clicking sensation occurs when the nodule moves through thetunnel formed by the pulley ligaments. With the finger straight, thenodule is at the far edge of the surrounding ligament. When the fingeris flexed, the nodule passes under the ligament and causes the clickingsensation. If the nodule becomes too large it may pass under theligament and become stuck at the near edge. The nodule cannot move backthrough the tunnel causing the finger to lock in the flexed triggerposition. Surgery may be required to release the trigger finger.

Trigger finger and tendon sheath surgery are common procedures that areusually performed in the operating room. A traditional tendon sheathrelease procedure is performed in an operating room at a hospital orsurgery center under conscious sedation—which involves risk to thepatient—and using a local anesthetic. The traditional open operationuses a conventional scalpel device and a 1.5 to 2.0 cm incision thatdisrupts all tissue and skin above the pulley and requires two or threestitches.

In U.S. patent application Ser. No. 12/896,088, incorporated herein byreference, Applicants disclosed a device and method for tendon sheathsurgery that allows the operation to be performed in a surgeon's officesafely, quickly, and in a less costly manner than going to the operatingroom. The current invention is an improvement upon the device disclosedin U.S. patent application Ser. No. 12/896,088 to ensure that othertissue is not damaged while the pulley is severed.

SUMMARY OF INVENTION

Generally speaking, the claimed invention is a precisely guided scalpeldevice having a protective cover over the blade that allows a surgeon toperform a tendon sheath release procedure safely and quickly in anoffice. The procedure is performed through an incision about 90 to 95%smaller than a conventional incision while at the same time allowing forminimal dissection of surrounding tissue and a more precise release ofthe pulley. Probes at the tip of the device allow the user to ensurethat the device is appropriately positioned under the pulley and, whenthis is confirmed under fluoroscopy or ultrasound, the protective coveris engaged and a cutting blade can be deployed to safely sever thepulley, thereby disturbing much less surrounding tissue than aconventional operation.

In an embodiment, a hemi-cannula is presented comprising: a tubularstructure having a proximal end, a distal end, a top portion and abottom portion; a slot disposed at the bottom portion of the distal end;and a sliding means disposed at the top portion. The top portion of thedistal end of the hemi-cannula may be tapered. The sliding means of thehemi-cannula may have at least one raised ridge.

A device for minimally invasive tendon sheath release having a staticblade is presented comprising: a handle having a cavity containedtherein; a sheath having a proximal and a distal end wherein theproximal end projects from the cavity and the distal end of the sheathhas a top and a bottom portion; a guide probe attached to the bottomportion of the distal end of the sheath; a dorsal outrigger guideattached at the top portion of the distal end of the sheath; a cuttingblade disposed between the guide probe and the dorsal outrigger guide; ahemi-cannula, having a slot and sliding means, disposed on the distalend of the sheath wherein the hemi-cannula may be moved proximally toexpose the guide probe or distally to contain the guide probe. Thesheath may be straight or curved. Both the guide probe and the dorsaloutrigger guide may have a spherical tip. The cutting blade may bestationary and disposed at an angle. The top portion of the distal endof the hemi-cannula may be tapered. The sliding means may have at leastone raised ridge.

In another embodiment, a device for minimally invasive tendon sheathrelease having a retractable blade is presented comprising: a handlehaving a cavity contained therein; a sheath having a proximal and adistal end wherein the proximal end projects from the cavity and thedistal end of the sheath has a top and a bottom portion; a guide probeattached to the bottom portion of the distal end of the sheath; a dorsaloutrigger guide attached at the top portion of the distal end of thesheath; a retractable cutting shaft slideably disposed within thesheath; a blade deployment switch located on the handle and inmechanical communication with the retractable cutting shaft, wherebyengaging the blade deployment switch deploys the retractable cuttingshaft; a hemi-cannula, having a slot and sliding means, disposed on thedistal end of the sheath wherein the hemi-cannula may be movedproximally to expose the guide probe or distally to contain the guideprobe.

The sheath may be straight or curved. Both the guide probe and thedorsal outrigger guide may have a spherical tip. The cutting blade maybe stationary and disposed at an angle. The top portion of the distalend of the hemi-cannula may be tapered. The sliding means may have atleast one raised ridge.

A sliding flag may be disposed within the cavity so that the slidingflag is in mechanical communication with the retractable cutting shaftand the blade deployment switch.

The dorsal outrigger guide may be extendable and retractable with theretractable cutting shaft. Both the guide probe and the dorsal outriggerguide may have a spherical tip. The retractable cutting shaft may have asharpened tip.

The top portion of the distal end of the hemi-cannula may be tapered.The sliding means may have at least one raised ridge.

In an embodiment, a method for minimally invasive tendon sheath releaseis presented, comprising the steps of: making an incision at, or justproximal to, a proximal flexion crease of a finger containing a pulley;inserting a guide of a device with a blade under an edge of the pulley;sliding a hemi-cannula over the guide whereby the guide, blade andpulley are contained within the hemi-cannula; deploying the blade of thedevice and pushing the device along the pulley to sever the pulley;retracting the device from the incision; and closing the incision.

A dilation device may be inserted prior to insertion of the guide inorder to dilate the incision area. The dilation device is then removedand the guide is inserted.

In an embodiment, a dilation device is presented comprising: a handlehaving a cavity contained therein; a sheath having a proximal and adistal end wherein the proximal end projects from the cavity and thedistal end of the sheath has a top and a bottom portion; a guide probeattached to the bottom portion of the distal end of the sheath; a dorsaloutrigger guide attached at the top portion of the distal end of thesheath; a cutting blade disposed between the guide probe and the dorsaloutrigger guide; and a dilation tip further comprising a tubularstructure having a proximal and a distal end wherein the distal end istapered. The dilation tip is disposed around the distal end of thesheath so that the guide probe, the dorsal outrigger guide and thecutting blade are contained within the dilation device.

BRIEF DESCRIPTION OF THE DRAWINGS

For a fuller understanding of the invention, reference should be made tothe following detailed description, taken in connection with theaccompanying drawings, in which:

FIG. 1 is a side view of an embodiment of the device utilizing thehemi-cannula.

FIG. 2 is a side view of the hemi-cannula in its retracted position onthe sheath of the device.

FIG. 3 is a perspective view of the hemi-cannula.

FIG. 4 is a side view of the hemi-cannula illustrating the slotpositioned at the bottom.

FIG. 5 is a perspective view of the device utilizing the hemi-cannula.

FIG. 6 is a perspective view of the device utilizing the hemi-cannula inthe retracted position.

FIG. 7 is a perspective view of the device utilizing the hemi-cannula inthe engaged position.

FIG. 8 is a side view of an embodiment of the device having a staticblade.

FIG. 9 is a side view of the static blade and guides.

FIG. 10 is a perspective view of an embodiment of the device utilizing ablade deployment mechanism.

FIG. 11 is a cross sectional side view of an embodiment of the deviceutilizing a blade deployment mechanism.

FIG. 12 is a side view of an embodiment utilizing an alternate bladedeployment mechanism.

FIG. 13 is a bottom view of an embodiment utilizing an alternate bladedeployment mechanism.

FIG. 14 is a side view of a commercial embodiment of the deviceutilizing a blade deployment mechanism

FIG. 15 is a top view of a commercial embodiment of the device utilizinga blade deployment mechanism.

FIG. 16 is a side view of an embodiment of the device having the dorsaloutrigger spherical tipped guide and retractable cutting shaft as onecomponent.

FIG. 17 is a side view of an embodiment of the device utilizing adilation tip.

FIG. 18 is a side view of the dilation tip.

FIG. 19 is a perspective view of the dilation tip.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In the following detailed description of the preferred embodiments,reference is made to the accompanying drawings, which form a parthereof, and within which are shown by way of illustration specificembodiments by which the invention may be practiced. It is to beunderstood that other embodiments by which the invention may bepracticed. It is to be understood that other embodiments may be utilizedand structural changes may be made without departing from the scope ofthe invention.

Generally, device 10 is comprised of handle 15, cavity 20, sheath 25,guide probe 30, dorsal outrigger guide probe 35, cutting blade 40 andhemi-cannula 45. Handle 15, as shown in FIGS. 1, 5, 8, 9, 12-15, and 17,includes a knurled rigid structure having dimensions of about 2.0 cmdiameter and about 7.0 cm in length. Handle may be constructed of arigid material including, but not limited to, a plastic, thermoplastic,acrylic, or metal. Handle 15 may be constructed of any shape but ispreferably constructed in a substantially round shape with hand gripspositioned on its proximal end. Handle may be solid or tubular havingcavity 20 disposed therein. Handle cavity 20 may be oriented in the longaxis of device 10, measuring about 1.5 cm by 1.3 mm by 1.0 cm deep.Handle cavity 20 originates on the surface and terminates at theequatorial center of device 10.

As depicted in FIGS. 1, 5, 10, 11, 12-15 and 17, sheath 25 extends fromhandle cavity 20 at distal end of handle 15. Sheath 25 has proximal anddistal ends as well as top and bottom portions. Sheath 25 may be ahollow tube having dimensions of about 6 cm in length andcross-sectional dimensions of about 2.5 mm by 1.0 mm. Sheath 25 attachesdistally to guide probe 30 and proximally to handle 15.

Guide probe 30 is attached to the bottom portion of sheath 25 andincludes an about 2.5 cm long stainless steel spherical tipped probethat tapers from its proximal to distal end, with a proximal rounddiameter of about 2.5 mm and a distal rounded diameter of about 1.0 mmwith an about 3.0 mm diameter spherical tip. Spherical tipped guideprobe 30 may be curved or straight. While the tip of guide probe isstated as being spherical-shaped, other shapes may be used with equaleffectiveness.

Device 10 also is comprised of dorsal outrigger guide 35, as shown inFIGS. 1 and 2, which includes an about 5 mm long by about 1 mm diameterstainless steel spherical tip outrigger that extends from the distal toppart of sheath 25 and has an about 2 mm diameter spherical tip at itsterminal end. Dorsal outrigger guide 35 may extend at an angle. Theangle may be about a 20 to 30 degree angle. While the tip of dorsaloutrigger guide probe is stated as being spherical-shaped, other shapesmay be used with equal effectiveness.

As shown in FIGS. 8 and 9, cutting blade 40 may be located at the distalend of sheath 25 between dorsal outrigger guide probe 35 and guide probe30. Specifically, FIGS. 2, 8, and 9 depict a static blade 40 disposed atthe apex of the two guide probes 30 and 35. Guide probe 30 may be turnedup to facilitate placement under the pulley. In use, the whole device ispushed forward to engage cutting blade 40 to sever the pulley.

Hemi-cannula 45, as depicted in FIGS. 1-7, is comprised of a tubularstructure having a proximal end, a distal end, a top portion, and abottom portion. The proximal portion of hemi-cannula has an openingdisposed therein into which sheath 25 is inserted. The top portion ofthe distal end of hemi-cannula 45 may be tapered downward to facilitateinsertion into the incision. The distal bottom portion of hemi-cannula45 contains slot 50. Slot 50 allows cutting blade 40, guide probe 30 anddorsal outrigger guide probe 35 to be contained within hemi-cannula 45while the pulley is being severed (FIG. 7). Sliding means 55 is disposedon top portion of hemi-cannula, thus permitting movement of hemi-cannula45 along longitudinal axis of sheath 25. Sliding means 55 may take anyform known by those in the art. Sliding means 55 may contain at leastone raised ridge to facilitate grip on hemi-cannula 45.

In use, device is inserted into incision with hemi-cannula 45 in aretracted position where the hemi-cannula is disposed more proximallyalong sheath 25 so that guide probe 30 is exposed (FIG. 6). In thisposition, cutting blade 40 is encased within hemi-cannula 45 thusprotecting surrounding tissue from being exposed to cutting blade 40. Inthe retracted position, there is about 1 cm between guide probe 30 anddistal tapered end of hemi-cannula 45. Once the pulley is located andverified, sliding means 55 is used to move hemi-cannula 45 distally downsheath 25 into the engaged position (FIG. 7) in which the pulley,cutting blade 40, dorsal outrigger guide probe 35 and guide probe 30 areencased within hemi-cannula 45. Device 10 is then pushed forward toengage cutting blade 40 to sever the pulley. Encasing the entire distalend of device 10 with the pulley allows severing of the pulley to beaccomplished without any potential damage to surrounding areas.Hemi-cannula 45 is depicted in FIGS. 1-7 as being used with a staticcutting blade, however in alternative embodiments, hemi-cannula 45 maybe used with a retractable or sliding blade with equal effectiveness.Hemi-cannula 45 may be constructed of any smooth, biocompatible, rigidmaterial known in the art including, but not limited to, athermoplastic, plastic, acrylic, glass, or metal.

FIGS. 10 and 11 depict an alternate embodiment of the device in which aretractable cutting blade is used. FIGS. 10 and 11 are depicted withouthemi-cannula 45 so that the mechanisms of the retractable cutting bladecan be shown. It should be noted however that hemi-cannula 45 can bepositioned in the same way as shown in FIGS. 6 and 7 to protectsurrounding areas while the pulley is being severed by retractablecutting blade. In this embodiment, sheath 25 contains retractablecutting shaft 60. Retractable cutting shaft 60 includes dimensions beingabout 7.5 cm in length with a cross-sectional dimension of about 0.7 mmby 2.2 mm. Retractable cutting shaft 60 may be constructed of a metalsuch as stainless steel. Retractable cutting shaft 60 includes a distalspade or square-shaped highly sharpened tip at the terminal end whichmay be considered as cutting blade 40. When not deployed, the spade tipresides about 3 mm proximal to the terminal end of sheath 25. In analternative embodiment, a sliding blade may be used instead of aretractable cutting shaft.

As depicted in FIG. 11, handle 15 contains an about 2.5 mm by 1.0 mmslot that contains the proximal extension of retractable cutting shaft60 to allows retractable cutting shaft 60 to attach to sliding flag 75.Sliding flag 75 is a substantially rectangular plate having dimensionsof about 1.0 mm by 10 mm by 1.5 mm. Sliding flag 75 may be constructedof a metal such as stainless steel. Sliding flag 75 attaches through aweld to retractable cutting shaft 60 inferiorly and is contained withinhandle cavity 20. Handle cavity 20 extends radially from the equatorialcenter of handle 15 about 1.0 cm to the surface. Sliding flag 75 is atabout 5 mm proximal to distal within handle cavity 20. Sliding flag 75attaches on its superior surface to blade deployment switch 70 by beingfirmly embedded in a slot in the base of the knob. Sliding flag 75 andswitch 70 essentially form a trigger mechanism for deploying cuttingshaft 60.

Blade deployment switch 70 may have dimensions of about 2.0 cm by 0.8 cmby 0.8 cm. Blade deployment switch 70 is attached firmly to sliding flag75 and allows the thumb of the device operator to deploy cutting blade40 once guide probe 30 is guided into position. Blade deployment switch70 may be constructed of any rigid material known by those in the artincluding, but not limited to, metal, plastic and acrylic.

Similarly to the device of FIGS. 1 and 5 featuring a static cuttingblade, guide probe 30 attaches to the bottom portion of the distal endof sheath 25. Dorsal outrigger guide probe 35 attaches to the topportion of the distal end of sheath 25. Sheath 25 contains retractablecutting shaft 60 which is used to cut the pulley tissue when deployed.Sheath 25 is attached to handle 15, which in turn contains a tunnel(that is essentially an extension of sheath 25 within handle 15) andhandle cavity 20 that contains and guides the proximal part ofretractable cutting shaft 60 and attached sliding flag 75. Sliding flag75 links retractable cutting shaft 60 to blade deployment switch 70.

The elements function together to act as a precise cutting guide for theA-1 pulley. In use, guide probe 30 is inserted through a small incisionsubcutaneously and is used to find the edge of the pulley. Once found,guide probe 30 is guided to the end of the pulley and its position isverified clinically and/or under radiographic or sonographic guidance.After proper position is assured, hemi-cannula 45 is moved into theengaged position to contain the guide probe 30, dorsal outrigger guideprobe 35, and retractable cutting shaft 60. The retractable cuttingshaft 60 is deployed by pushing and holding blade deployment switch 70.The sharp spade tip of retractable cutting shaft 60 is extended about 3mm beyond sheath 25 but is still contained within hemi-cannula 45.Device 10 is then pushed utilizing handle 15 along the pulley about 1 to2 cm until the pulley is completely released or where resistance is nolonger felt.

FIGS. 12 and 13 depict an alternate deployment mechanism for extendingand retracting deployable blade 90. Specifically, blade deploymentswitch 70 and retractable cutting shaft 60 are in mechanicalcommunication via a lever.

Similarly, FIGS. 14 and 15 depict an alternate deployment mechanism forextending and retracting blade 40. In FIGS. 14 and 15, wire 80 extendsthrough sheath 25 attached to retractable cutting shaft 60 allowing itto be retracted to the level of dorsal outrigger guide probe 35 so theinstrument can be placed safely in the blunt mode. Retractable cuttingshaft 60 may be deployed and device 10 pushed forward to divide thepulley.

In an alternate embodiment, as shown in FIG. 16, dorsal outrigger guideprobe 35 is disposed at the top, distal end of retractable cutting shaft60. Because dorsal outrigger guide probe 35 is disposed at the top,distal end of retractable cutting shaft 60, they both extend and retracttogether as retractable cutting shaft 60 is deployed. Instead of twoseparate components, the two are essentially formed as one component.

In an embodiment of the present invention, a method of performingminimally invasive tendon sheath release is presented. First, thepatient's finger is anesthetized with lidocaine infiltration using aneedle and syringe at the level of the distal palmar crease directlyover the A1 pulley and palmar digital crease. A small puncture incisionis then made over the palmar digital crease centrally using a #11 blade.Guide probe 30 is introduced centrally and subcutaneously over thetendon sheath and directed down at about a 45 degree angle. Throughprobing with guide probe 30, the distal edge of the A1 pulley is locatedand guide probe 30 is passed below the pulley from distal to proximal inline with the flexor tendon until it is felt to push beyond the leadingedge of the A1 pulley. The placement of guide probe 30 is verifiedclinically by wiggling it back and forth in the plane of the operatingsurface to make sure guide probe 30 is contained in the pulley. Theplacement of guide probe 30 and avoidance of the digital vessels is thenconfirmed under ultrasound guidance. Once correct placement isconfirmed, hemi-cannula 45 is engaged by using sliding means 55 to pushhemi-cannula 45 over guide probe 30 thus containing the pulley withinslot 50 of hemi-cannula 45 and protecting the surrounding areas fromdamage. The retractable cutting shaft 60 having a sharp tip is deployedby pushing blade deployment switch 70 and device 10 is pushed centrallyand proximally along the A1 pulley until the pulley is severed.

In an alternative embodiment, dilation tip 85 may be used to dilate thearea prior to insertion of the guide probe 30. As depicted in FIGS.17-19, dilation tip 85 is a tubular structure having a proximal and adistal end. The distal end may be tapered. In use, distal end of sheath25 is inserted into proximal end of dilation tip 85 so that dilation tip85 is positioned around the distal end of sheath 25 to completely encaseguide probe 30, dorsal outrigger guide probe 35 and cutting blade 40.Dilation device 10 is inserted into incision to dilate the incision.Dilation device 10 is then removed once the incision is dilated.Dilation tip 85 may be removed from distal end of sheath 25 and replacedwith hemi-cannula 45. Device with hemi-cannula 45 in the retractedposition to expose spherical tipped guide probe 30 is then inserted intothe dilated incision and locating and severing the pulley is completedas detailed above. Dilation tip 85 can be constructed of any rigidmaterial including, but not limited to, glass, plastic, metal, acrylic,and thermoplastic.

In other embodiments, device 10 is used to release other tendon sheathsand slips of tissue in the body by providing safe subcutaneous guidanceand subsequent effective cutting. Device 10 can be used unmodified forDeQuervain's release, posterior tibial tendon release, tarsal tunnelrelease, and, through a variation of guide probe 30 concept and devicesize, be used to perform a carpal tunnel release with ultrasoundguidance through a small puncture incision and a plantar fascialrelease. Variations can also be used to perform fasciotomy incisions inthe leg and forearm for compartment syndromes.

In the preceding specification, all documents, acts, or informationdisclosed does not constitute an admission that the document, act, orinformation of any combination thereof was publicly available, known tothe public, part of the general knowledge in the art, or was known to berelevant to solve any problem at the time of priority.

The disclosures of all publications cited above are expresslyincorporated herein by reference, each in its entirety, to the sameextent as if each were incorporated by reference individually.

It will thus be seen that the objects set forth above, and those madeapparent from the foregoing disclosure, are efficiently attained. Sincecertain changes may be made in the above construction without departingfrom the scope of the invention, it is intended that all matterscontained in the foregoing disclosure or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

It is also to be understood that the following claims are intended tocover all of the generic and specific features of the invention hereindisclosed, and all statements of the scope of the invention that, as amatter of language, might be said to fall therebetween. Now that theinvention has been described,

What is claimed is:
 1. A device for minimally invasive tendon sheathrelease comprising: a handle having a cavity contained therein; a sheathhaving a proximal and a distal end wherein the proximal end projectsfrom the cavity and the distal end of the sheath has a top and a bottomportion; a guide probe having a spherical tip attached to the bottomportion of the distal end of the sheath; a dorsal outrigger guide havinga spherical tip attached at the top portion of the distal end of thesheath; a retractable cutting shaft slideably disposed within thesheath; and a blade deployment switch located on the handle and inmechanical communication with the retractable cutting shaft, wherebyengaging the blade deployment switch deploys the retractable cuttingshaft.
 2. The device of claim 1, further comprising a hemi-cannuladisposed on the distal end of the sheath comprising: a tubular structurehaving a proximal end, a distal end, a top portion and a bottom portionwherein distance between the proximal end and the distal end define alongitudinal distance of the tubular structure; a rounded openingdisposed in the proximal end adapted to receive a device for minimallyinvasive tendon sheath release; and a sliding means disposed at theproximal end of the top portion; wherein the top portion of the distalend is downwardly tapered; wherein the bottom portion extends distallyfrom the opening for less than half of the longitudinal distance of thetubular structure; wherein the hemi-cannula may be moved proximally toexpose the guide probe or distally to contain the guide probe.
 3. Thedevice of claim 1, further comprising a sliding flag disposed within thecavity wherein the sliding flag is in mechanical communication with theretractable cutting shaft and the blade deployment switch.
 4. The deviceof claim 1, wherein the dorsal outrigger guide is extendable andretractable with the retractable cutting shaft.
 5. The device of claim1, wherein the retractable cutting shaft has a sharpened tip.
 6. Thedevice of claim 2, further comprising the sliding means having at leastone raised ridge.
 7. A method for minimally invasive tendon sheathrelease, comprising the steps of: making an incision at, or justproximal to, a proximal flexion crease of a finger containing a pulley;inserting a device for minimally invasive tendon sheath release under anedge of the pulley wherein the device is comprised of a handle having acavity contained therein; a sheath having a proximal and a distal endwherein the proximal end projects from the cavity and the distal end ofthe sheath has a top and a bottom portion; a guide probe having aspherical tip attached to the bottom portion of the distal end of thesheath; a dorsal outrigger guide having a spherical tip attached at thetop portion of the distal end of the sheath; a retractable cutting shaftslideably disposed within the sheath; and a blade deployment switchlocated on the handle and in mechanical communication with theretractable cutting shaft; deploying the retractable cutting shaft ofthe device to cut the pulley by engaging the blade deployment switch;retracting the device from the incision; and closing the incision;wherein the spherical tipped guide probe is positioned under the edge ofthe A-1 pulley.
 8. The method of claim 7, wherein the device forminimally invasive tendon sheath release further comprises ahemi-cannula disposed on the distal end of the sheath comprising: atubular structure having a proximal end, a distal end, a top portion anda bottom portion wherein distance between the proximal end and thedistal end define a longitudinal distance of the tubular structure; arounded opening disposed in the proximal end adapted to receive a devicefor minimally invasive tendon sheath release; and a sliding meansdisposed at the proximal end of the top portion; wherein the top portionof the distal end is downwardly tapered; wherein the bottom portionextends distally from the opening for less than half of the longitudinaldistance of the tubular structure.
 9. The method of claim 8, furthercomprising sliding the hemi-cannula over the guide probe beforedeploying the retractable cutting shaft whereby the guide probe, bladeand pulley are contained within the hemi-cannula.
 10. The method ofclaim 7, further comprising injecting a local anesthetic at level of anA-1 pulley in a finger prior to making the incision at the proximalflexion crease of the finger.
 11. The method of claim 7, furthercomprising inserting a dilation device prior to insertion of the guideto dilate the incision area.
 12. The method of claim 7, furthercomprising verifying the placement of the device by wiggling it back andforth in a plane of an operating surface to ascertain that the device iscontained in the A-1 pulley.
 13. The method of claim 7, furthercomprising confirming placement of the device by ultrasonic orfluoroscopic imaging.